Improve ViewLocalizer resource look-up semantics:

- Always prepend with application name and let underlying `IStringLocalizerFactory` do the name gymnastics
- Use ExecutingFilePath instead of view name
- Trim off the file extension (so your resource doesn't have to have ".cshtml" in its name)
- Improved doc comments
- #3718

src/Microsoft.AspNet.Mvc.Localization/IViewLocalizer.cs

@@ -4,7 +4,7 @@
 namespace Microsoft.AspNet.Mvc.Localization
 {
     /// <summary>
-    /// A service that provides localized strings for views.
+    /// Represents a type that provides HTML-aware localization for views.
     /// </summary>
     public interface IViewLocalizer : IHtmlLocalizer
     {

src/Microsoft.AspNet.Mvc.Localization/ViewLocalizer.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.IO;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.Localization;
@@ -12,7 +13,8 @@
 namespace Microsoft.AspNet.Mvc.Localization
 {
     /// <summary>
-    /// A <see cref="IHtmlLocalizer"/> implementation that provides localized strings for views.
+    /// An <see cref="IViewLocalizer"/> implementation that derives the resource location from the executing view's
+    /// file path.
     /// </summary>
     public class ViewLocalizer : IViewLocalizer, ICanHasViewContext
     {
@@ -93,12 +95,18 @@ public void Contextualize(ViewContext viewContext)
                 throw new ArgumentNullException(nameof(viewContext));
             }
 
-            var baseName = viewContext.View.Path.Replace('/', '.').Replace('\\', '.');
-            if (baseName.StartsWith(".", StringComparison.OrdinalIgnoreCase))
+            // Trim the file extension from the end of the path
+            var path = viewContext.ExecutingFilePath;
+            if (Path.HasExtension(path))
             {
-                baseName = baseName.Substring(1);
+                var extension = Path.GetExtension(path);
+                path = path.Substring(0, path.Length - extension.Length);
             }
 
+            var baseName = path.Replace('/', '.').Replace('\\', '.');
+            baseName = baseName.TrimStart('.');
+            baseName = _applicationName + "." + baseName;
+
             _localizer = _localizerFactory.Create(baseName, _applicationName);
         }
     }